Voice quality outcome becomes an important factor in the choice of the therapeutic option. The differences between radiotherapy and laser cordectomy have been extensively debated in the literature. We analyzed the vocal outcomes after carbon dioxide (CO2) laser cordectomy and radiotherapy treatment for T1a-b early glottic cancer by means of objective and subjective voice evaluation. A retrospective study was performed on 56 cancer patients, 30 treated with cordectomy and 26 with radiotherapy. All patients underwent laser cordectomy which was performed under general anesthesia using a surgical microscope in laryngeal suspension. The laser we used was an Ultrapulse one, 10.6-μm wavelength, and a power setting of 2 to 4 W in an Ultrapulse mode was selected. Two different sets of data were recorded: (a) voice acoustic analysis (jitter, shimmer, fundamental frequency and noise/harmonic ratio) and (b) voice handicap index (VHI). Data collected were statistically analyzed using SPSS 20.0 for Windows. Jitter, shimmer, and signal-to-noise ratio were significantly altered in both glottic cancer patient groups as compared to the control group. On the contrary, no statistically significant alteration of the fundamental frequency was found in both treatment groups. Interestingly, jitter and shimmer values were significantly more compromised in transoral laser surgery patients as compared with radiotherapy-treated patients. The VHI was also significantly altered in both cancer patient groups as compared to the control group. More importantly, however, the self-evaluation voice analysis was not significantly different between the two treatment groups, contrary to what we observed for two of the four parameters measured in the objective voice analysis. Given the importance of the self-perception of the voice quality, no treatment can be considered superior from the patients' point of view. Therefore, we suggest that priority should be given to the endoscopic surgery, due to lower costs, lower morbidity, and shorter hospitalization.
Keywords: Glottic cancer; Larynx; Radiotherapy; Transoral carbon dioxide (CO2) laser cordectomy; Voice; Voice handicap index (VHI).